Two column lifting platform

ABSTRACT

There is disclosed a two-column lifting platform with spindleoperated lifting carriage, e.g., for use in lifting motor vehicles, for example, for the purpose of inspection and maintenance, which comprises a carriage forming or carrying a platform for supporting the vehicle to be lifted, and two columns for moving the carriage vertically. At least one column comprises a threaded spindle carrying a nut secured to the lifting carriage, rotation of the spindle thus displacing the carriage. The carriage is also guided in its vertical movements by suitable lateral guide means. The spindle passes through a stepped bore in the lifting carriage, wherein a ring of oil-absorbent material is fitted in the stepped bore so that the inside peripheral face of the ring lies in an oil-transferring relationship against the periphery of the spindle and the ring is held in position by a flange sleeve which is pressed into the stepped bore and which defines a space for containing lubricating oil, the flange portion of the flange sleeve having one or more openings through which oil can flow to saturate the ring.

United States Patent 1 Fricke [54] TWO-COLUMN LIFTING PLATFORM [75]Inventor: Heinz Fricke, Pfungstadt, Germany [73] Assignee: Gehr. HofmannKG. Machinenfabrik, Darmstadt, Germany 22 Filed: Oct.22, 1971 21Appl.No.: 191,878

[56] References Cited UNITED STATES PATENTS 2,800,200 7/1972 Wallace..187/8.59 2,742,257 4/1956 Hott ....254/7 B 3,489,395 l/l970 Glassmeyer..254/86 R Mar. 27, 1973 Primary ExaminerOthell M. Simpson AssistantExaminer-Robert C. Watson Attorney-Cushman, Darby & Cushman [57]ABSTRACT There is disclosed a two-column lifting platform withspindle-operated lifting carriage, e.g., for use in lifting motorvehicles, for example, for the purpose of inspection and maintenance,which comprises a carriage forming or carrying a platform for supportingthe vehicle to be lifted, and two columns for moving the carriagevertically. At least one column comprises a threaded spindle carrying anut secured to the lifting carriage, rotation of the spindle thusdisplacing the carriage. The carriage is also guided in its verticalmovements by suitable lateral guide means. The spindle passes through astepped bore in the lifting carriage, wherein a ring of oil-absorbentmaterial is fitted in the stepped bore so that the inside peripheralface of the ring lies in an oil-transferring relationship against theperiphery of the spindle and the ring is held in position by a flangesleeve which is pressed into the stepped bore and which defines a spacefor containing lubricating oil, the flange portion of the flange sleevehaving one or more openings through which oil can flow to saturate thering.

8 Claims, 8 Drawing Figures PATENTEUHARZYIQYE SHEET 1 [)F 4 FIG. 2

PAIENIEDHIIRZY I975 SHEET 2 [IF 4 FIG. 3

FIG. 4

FIG. 6

PATEN TU] AR 2 71375 SHEET 30F 4 FIG.?

TWO-COLUMN LIFTING PLATFORM BACKGROUND OF THE INVENTION In known liftingplatforms, lubrication of the spindles is essential but can also beexpensive and difficult. Either an oil pump is fitted for force-feedlubrication, or lubrication is effected continuously by hand, which is acomplicated procedure often resulting in irregular lubrication. There isalso the possibility of splash lubrication. In this case, a pick-updevice dips into an oil reservoir and, as the lifting carriage israised, applies oil to the spindle. A disadvantage of this kind oflubrication, however, is that the bottom spindle threads may receiveplenty of oil, but the upper spindle threads receive less oil or even nooil at all.

Lifting nuts for cooperation with the threaded spindles are known, whichare made entirely from bearing metal such as babbitt metal. Theexpensive bearing metals increase the cost of the lifting nuts. Eitherthe breaking or tensile strength of the nuts may not be sufficient,owing to the nuts being made exclusively of bearing metal, or the forcesacting on the nuts had to be allowed for by making the lifting nuts oflarger dimen- SIOIIS.

SUMMARY OF THE INVENTION Accprding to the present invention, there isprovided a two-column lifting platform for lifting a motor vehicle,comprising two columns and a rotary spindleoperated lifting carriageguided by the columns, the spindle passing through a stepped bore in thelifting carriage, wherein a ring of oil-absorbent material is fitted inthe stepped bore so that the inside peripheral face of the ring lies inan oil-transferring relationship against the periphery of the spindleand the ring is held in position by aflange sleeve which is pressed intothe stepped bore and which defines a space for containing lubricatingoil, the flange portion of the flange sleeve having one or more openingsthrough which oil can flow to saturate the ring.

BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of a lifting platformaccording to the present invention will now be described by way ofexample with reference to the accompanying drawings in which:

FIG. 1 shows a longitudinal section through a part of a lifting spindleshowing the lubrication thereof;

FIG. 2 shows a partial section through part of a lifting carriage withspindle and guide means;

FIG. 3 shows a front elevation view of the lifting platform;

FIG. 4 shows a partial section of the lifting platform on line44 of FIG.3;

FIG. 5 shows a plan view of one lifting nut; and

FIG. 6 shows a section of the lifting nut on line 66 of FIG. 5.

FIG. 7 is a fragmentary side elevation view with parts in section of thebase region of one spindle showing portions of the lifting carriageguide means and lubricator; and

FIG. 8 is a horizontal transverse sectional view generally comparablewith the region depicted in FIG. 2.

As shown in FIG. 1, a ring 2 made of felt or another absorbent materialis fitted into a stepped bore 1 in the lifting carriage. The ring 2 isprevented from moving in a vertical direction within the bore 1 by aflanged sleeve 4 which is a press fit in the bore 1, above the ring 2,the flange portion of the sleeve 4 being of a diameter to ensure a firmseat in the bore 1 and at the same time oil-tightly closing the bore 1towards the ring 2. The sleeve 4 is also pressed into the bore 1 to adepth such that the ring 2 cannot move in a radial direction, but isfirmly held in place. The outside diameter of the ring 2 issubstantially equal to that of the bore 1, while its inside diameter issomewhat smaller than the diameter of a lifting spindle 3 which passescentrally through the bore in the carriage. As a result, the innervertical peripheral face of the ring 2 lies closely against the outsideperiphery of the lifting spindle 3. The ring 2 is continuously saturatedwith highviscosity oil through one or more openings 5 in the flangeportion of the sleeve 4 from an annular space 6 formed between theoutside face of the sleeve portion of the sleeve 4 and the surroundingpart of the lifting carriage the sleeve portion being of substantiallysmaller outside diameter than theflange portion and larger in insidediameter than the spindle 3 to ensure free motion. The ring 2 thus formsan oil reserve and, moving up and down along the spindle 3 as the latterrotates, provides lubrication thereof in any lifting position of thecarriage.

Referring now to FIG. 2, the lifting carriage 20 is guided by means ofsupport rollers 9 carried on cantilevered, i.e., overhung, shafts.Secured to the free end face of each of the overhung shafts is arespective slide member 7 whichguides the carriage laterally, by slidingagainst vertical structural members or tracks 17. The slide members 7are held in position by means of countersunk cylinder bolts or screws 8,and also prevent the tional force could be exerted on the slide members7 by frictional contact with the end face of the rotating rollers 9,such a rotational. force tending if unchecked to twist the slide members7 and thereby loosen the bolts or screws 8, the slide members 7 arc alsosecured in position relative to the shafts of the rollers 9 by securingmeans such as one or more offset pins 10 or the like members engaged inthe slide members 7 and associated shafts. The slide members 7 are, forexample, circular and are mounted coaxially to the rollers 9.

The FIG. 2 arrangement has the advantage that the lifting carriage withits guide means is of less structural height than previously proposedconstructions in which the rollers and slide members are arranged oneabove the other.

In FIGS. 3 and 4, a carrier member 11 which is secured to the liftingcarriage and which pivotally carries support arms with support platemembers 12 for carrying a vehicle to be lifted, is extended beyond thewidth of a base'frame member 13 at the foot of the vertical column. Thepivotal connections between carrier member 11 andthe support arms thuslie outside the member 13, so that the support arms can be'lowered to aposition in which they are almost flush with the road way surface onwhich the lifting platform is standing.

ground clearance, without the arms coming to rest on the frame members13 and being impeded in their downward movement. The arms are pivotedunder the vehicle to be lifted.

FIGS. 5 and 6 show the construction of the lifting nut which cooperateswith the lifting spindle 3 of FIG. 1, rotation of the spindle moving thenut, and therewith the carriage 20 in which the nut is carried, in avertical direction. A flanged sleeve comprising bearing metal and havingan internal thread mating with the thread of the lifting spindleispressed into a stepped bore in a steel sleeve 14 which is secured in.the lifting carriage. The weight of the carriage and any .load thereonwill tend to force the flanged sleeve 15 into the steel sleeve 14, theflanged portion of the sleeve 15 bearing the weight on its upwardsurface, as is clearly shown in FIG. 6. One or more securing memberssuch as a pin 16 or like member prevent relative rotational movementbetween the two sleeves 14 and 15. The nut thus enjoys a high tensilestrength, by virtue of the steel sleeve 14, while the cost of the nut isreduced relative to a nut made entirely of bearing metal, as thedimensions of the inner sleeve 15 can be kept to a minimum compatiblewith safe reliable operation.

It should now be apparent that the two-column lifting platform asdescribed hereinabove possesses each of the attributes set forth in thespecification under the heading Summary of the Invention hereinabove.Because the two-column lifting platform of the invention can be modifiedto some extent without departing from the principles of the invention asthey have beenoutlined and explained in this specification, the presentinvention should be understood as encompassing all such modifications asare within the spirit and scope of the following claims.

' What is claimed is:

1. A two-column lifting platform for lifting a motor vehicle,comprising:

two upright columns; a lifting carriage; a rotatable spindle; meansconnecting the rotatable spindle to the lifting carriage for raising andlowering the carriage upon rotation of the spindle; I means on thelifting carriage engageable with at least one of the columns for guidingthe carriage with respect to the at. least one column when the carriageis being raised and lowered; means defining an opening in the liftingcarriage having means defining an upwardly facing annular shouldertherein; an annular ring of lubricating oil-absorbent material disposedupon said shoulder with the inner peripheral surface thereof in oiltransferring engagement with the external peripheral surface of therotatable spindle; a tubular sleeve received within said opening, saidtubular sleeve having means defining an annular, downwardly facingflange thereon at the lower end thereof disposed to engage said annularring of lubricating oil-absorbent material;

said tubular sleeve, above said flange thereof being annularly spacedradially inwardly from the periphery of said opening to define betweenthe periphery of said opening and the exterior of said tubular sleeve,above said flange thereof, a

lubricating oil reservoir; means on said carriage maintaining saidtubular sleeve fixed with respect to said opening in the dispositionwith respect to the annular ring as recited; and

means defining at least one port through the flange of said tubularsleeve communicating the lubricating oil reservoir with the annular ringof lubricating oil-absorbent material.

2. A lifting platform according to claim 1 wherein the ring is made offelt.

3. A lifting platform according to claim 1 wherein the means for guidingthe carriage comprises at least two overhung shafts on the liftingcarriage, each of the. shafts carrying a guide roller and having a slidemember secured to the end face of the shaft, the rollers and the slidemembers guidingly locating the lifting carriage respectively intwohorizontal directions perpendicular to each other.

4. A lifting platform according to claim 3 wherein each slide member isconnected to the associated shaft by a screw connection, at least oneadditionalsecuring member being provided to prevent the slidememberrotating relative to the respective shaft.

5. A lifting platform according to claim 4 wherein the slide members arecircular and are mounted coaxially relative to the respective shafts.

6. A lifting platform according to claim 1 further comprising a baseframe member physically interconnecting the two columns at. the foot ofeach column wherein the lifting carriage carries a carrier member towhich vehicle support arms are pivotally connected, the carrier-memberbeing extended so that the arm pivotal connections-lie outside the widthof the base frame member at the feet of the columns.

7. A lifting platform according to claim 1 wherein means connecting therotatable spindle to the lifting carriage comprises a lifting nut whichcooperates with the spindle to move the lifting carriage vertically, thelifting nut comprising a steel sleeve and a flanged sleeve which ispressed into the steel sleeve and which is made of bearing metal, theflanged sleeve having means defining internal threading cooperating withmeans defining external threading on the spindle.

8. A lifting platform according to claim 7 wherein a securing pin.engages into the steel sleeve and the flange sleeve, to prevent relativerotation therebetween.

i I! 1 t I

1. A two-column lifting platform for lifting a motor vehicle,comprising: two upright columns; a lifting carriage; a rotatablespindle; means connecting the rotatable spindle to the lifting carriagefor raising and lowering the carriage upon rotation of the spindle;means on the lifting carriage engageable with at least one of thecolumns for guiding the carriage with respect to the at least one columnwhen the carriage is being raised and lowered; means defining an openingin the lifting carriage having means defining an upwardly facing annularshoulder therein; an annular ring of lubricating oil-absorbent materialdisposed upon said shoulder with the inner peripheral surface thereof inoil transferring engagement with the external peripheral surface of therotatable spindle; a tubular sleeve received within said opening, saidtubular sleeve having means defining an annular, downwardly facingflange thereon at the lower end thereof disposed to engage said annularring of lubricating oil-absorbent material; said tubular sleeve, abovesaid flange thereof being annularly spaced radially inwardly from theperiphery of said opening to define between the periphery of saidopening and the exterior of said tubular sleeve, above said flangethereof, a lubricating oil reservoir; means on said carriage maintainingsaid tubular sleeve fixed with respect to said opening in thedisposition with respect to the annular ring as recited; and meansdefining at least one port through the flange of said tubular sleevecommunicating the lubricating oil reservoir with the annular ring oflubricating oil-absorbent material.
 2. A lifting platform according toclaim 1 wherein the ring is made of felt.
 3. A lifting platformaccording to claim 1 wherein the means for guiding the carriagecomprises at least two overhung shafts on the lifting carriage, each ofthe shafts carrying a guide roller and having a slide member secured tothe end face of the shaft, the rollers and the slide members guidinglylocating the lifting carriage respectively in two horizontal directionsperpendIcular to each other.
 4. A lifting platform according to claim 3wherein each slide member is connected to the associated shaft by ascrew connection, at least one additional securing member being providedto prevent the slide member rotating relative to the respective shaft.5. A lifting platform according to claim 4 wherein the slide members arecircular and are mounted coaxially relative to the respective shafts. 6.A lifting platform according to claim 1 further comprising a base framemember physically interconnecting the two columns at the foot of eachcolumn wherein the lifting carriage carries a carrier member to whichvehicle support arms are pivotally connected, the carrier member beingextended so that the arm pivotal connections lie outside the width ofthe base frame member at the feet of the columns.
 7. A lifting platformaccording to claim 1 wherein means connecting the rotatable spindle tothe lifting carriage comprises a lifting nut which cooperates with thespindle to move the lifting carriage vertically, the lifting nutcomprising a steel sleeve and a flanged sleeve which is pressed into thesteel sleeve and which is made of bearing metal, the flanged sleevehaving means defining internal threading cooperating with means definingexternal threading on the spindle.
 8. A lifting platform according toclaim 7 wherein a securing pin engages into the steel sleeve and theflange sleeve, to prevent relative rotation therebetween.